PanelView 300 Alarm Banner

[robh 12]

I have a Panelview 300 standard terminal. I am using the alarm banner to record events to be displayed on the screen. Whenever an event occurs, a number is moved into an integer file (in a MicroLogix 1200) and in turn tells the panelview that a corresponding alarm condition (event) is present. This number is in the integer file for about a 2 seconds, then a zero is moved in to represent no alarms. The problem I am having is that it is missing some events. This PV has been in service for about 2 years. I have ordered a new one but I am very puzzled about why it is all the sudden not working right. Heck I don't even know if this makes any sense! I have a hard time with the idea that the PV is worn out. Any ideas?

[TimWilborne 108]

Have you thought about using Handshake and Notification tags to assure that the Panelview is logging the alarms before you clear the integer? I know this doesn't explain your problem but it may fix it.

[robh 12]

No I haven't tried that yet, but sounds like a good idea. I am kinda excited to see what happens with the new PV. What a dork I am!

[Stupidav 1]

For that matter rather than just having the bit set fo 2 seconds, why not have the panelview togle it off, via the alarm acknoledge?

[BobLfoot 301]

You don't mention the communication media between the 1200 and the PV. Is it serial or networked. if networked I'd suspect a change in network traffic tying up the token and causing some messages not to reach the PV. If Serial I'd check the 1200 program for recent changes that might affect scan time.

[robh 12]

DH-485 with Net-AIC, Just the Micro and PV Edited 21 Apr 2006 by robh

[BobLfoot 301]

This is a straw grasp but have you checked your Dh-485 connections. They can corrode and loosen with age resulting in poor connection quality and noise forcing resends of data and a longer response time. You also might want to look if there has been any equipment added along the DH-485 wire run. Noise is another issue.

[TimWilborne 108]

Just another straw grasp. Is it possible that the alarms were so minor that no one ever noticed that they were being lost. A mechanical thing or a a real picky operator brought the lost alarms to light and the handshake and notification tags should have in the program initially?

[robh 12]

There hasn't been any new equipment added, but I will check and or just replace the cables to make sure there is no problem there. So simple, but probably very effective! Thanks for all the ideas. Edited 24 Apr 2006 by robh